Multiprotocol Antenna For Wireless Systems
There is an antenna, three feed ports, two switches, and two impedances. In an embodiment, the first and second feed ports interface respective FM transmitter and FM receiver, and the third feed port interfaces Bluetooth, WLAN and/or GPS radios. The two switches are disposed along the antenna. A first throw of them renders a balanced mode for the antenna seen by the first feed port and a second throw renders an unbalanced mode for the antenna seen by the second feed port. The two impedances are disposed and configured such that the antenna, for signals in a second frequency band at the third feed port and which are impeded by the two impedances, is an unbalanced mode for the first throw of the switches and is an unbalanced mode for the second throw of the switches. Also detailed is a method for making an electronic device having such an antenna.
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This application is a continuation in part of U.S. patent application Ser. No. 12/387,355, filed on Apr. 30, 2009, and claims benefit thereof under 35 USC§120 and 37 CFR§1.53(b)(2).
TECHNICAL FIELDThe example and non-limiting embodiments of this invention relate generally to wireless communication systems, methods, devices and computer programs and, more specifically, relate to an antenna for use in different radio technologies.
BACKGROUNDThis section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Increasingly, mobile radio handsets incorporate multiple radios that operate over different protocols and different frequency bands. For example, it is typical that a new mobile handset is equipped with one or more of a global positioning system GPS receiver, a Bluetooth transceiver, a wireless local area network WLAN transceiver, and a traditional FM radio receiver. More prevalent currently in Europe and Asia than in the US, some mobile handsets also incorporate a radiofrequency identification RFID transceiver, which is often used for mobile electronic commerce when linked to a credit/debit card, for electronic keys (car, house, etc.), and/or for reading a passive RFID tag (e.g., interactive advertising). RFID has a viable signal range of about 10 centimeters and operates in the 13.56 MHz frequency band. All of these radios above can generally be considered as secondary radios, in contrast to a cellular transceiver which may be considered the primary radio of a mobile telephony handset. Note also that it is common for such handsets to have multiple primary radios (e.g., tri-band or quad-band) for communicating on different cellular protocols such as GSM (global system for mobile communications, or 3 G), UTRAN (universal mobile telecommunications system terrestrial radio access network, or 3.5 G), WCDMA (wideband code division multiple access), OFDMA (orthogonal frequency division multiple access), to name but a few examples.
Each of these radios must operate with an antenna tuned to the requisite frequency band. Typically, near-field communications (NFC, a regime in which RFID is a member), Bluetooth, WLAN, and GPS are implemented with separate antennas. Where the handset also includes an internal FM radio, typically there is also an internal FM receiver including antenna (FM-RX) and an internal FM transmitter with an antenna (FM-TX) that may be separate from the FM-RX antenna.
All of this hardware of course must be fit into a handheld-size package, of which the housing itself must either facilitate the proper antenna resonances or not interfere with such proper resonances. This problem of space is increasingly acute considering the current trend toward metallic handset housings/covers/casings as compared to plastic which was recently the most common material for mobile phone housings. Often in past handset layouts there was a separate antenna for Bluetooth and WLAN, for GPS, for NFC, and for FM radio (broadcast), as well as for the primary cellular radio(s). While the Bluetooth, WLAN and GPS antennas can be made quite small, the FM antenna(s) require much more space, particularly if they are implemented separately for receive RX and transmit TX events.
Another challenge in antenna design for mobile handsets is output power, particularly for FM transmitting. Space may be saved by combining a Bluetooth/WLAN antenna to a FM band radiator, which is typically larger as compared to a stand-alone Bluetooth/WLAN antenna anyway. Such a combined arrangement often uses an unbalanced (non-loop) configuration for the FM TX antenna. The additional challenge with such a combined antenna arrangement is to get sufficient output power for the FM TX function. Of course, satisfying the space issue noted above gives the designer fewer choices by which to solve the power issue.
Specific implementations for multiplexing multiple radios into a single antenna are detailed at U.S. Pat. Nos. 6,950,410 and 7,376,440. Peter Lindberg and Andrei Kaikkonen describe, at an Internet publication entitled “BUILT-IN HANDSET ANTENNAS ENABLE FM TRANSCEIVERS IN MOBILE PHONES” (July, 2007), a FM transceiver antenna designed for a handset that is a single turn half-loop, shorted at one end and connected at the other to a co-designed preamplifier which also has a shunt capacitor for ac shorting at GSM frequencies.
SUMMARYIn a first aspect the exemplary embodiments of the invention provide an apparatus comprising an antenna, first second and third feed ports, at least two switches, and at least two impedances. The first feed port defines a first end of the antenna and the second feed port defines a second end of the antenna. The third feed port interfaces to the antenna at an intermediate point between the first and second ends. Each of the at least two switches comprising at least a first throw and a second throw. The two switches are disposed in series along the antenna and configured such that the first throw of the switches renders a balanced mode for the antenna as seen by the first feed port and the second throw of the switches renders an unbalanced mode for the antenna as seen by the second feed port. The at least two impedances are disposed along the antenna and configured such that the antenna, as seen by signals in a second frequency band at the third feed port and which are impeded by the at least two impedances, is an unbalanced mode for the first throw of the switches and is an unbalanced mode for the second throw of the switches.
In a first aspect the exemplary embodiments of the invention provide a method comprising: operatively coupling a transmitter to an antenna in a balanced mode via a first feed port and a first throw of a first switch and a first throw of a second switch; operatively coupling a receiver to the antenna in an unbalanced mode via a second feed port and a second throw of the second switch; operatively coupling at least a second radio, configured to operate in a frequency band different from the transmitter and from the receiver, to the antenna via a third feed port that interfaces to the antenna at an intermediate point between the first switch and the second switch; and moving the first and second switches to the first throw in correspondence with a transmission from the transmitter.
In the example embodiment of
Separation of signals, for example from the different NFC and FM (-RX) systems, could be difficult without the use of filters and without losing at least partially some of the received or transmitted signal power. Even connecting only two disparate systems like NFC and FM-RX to the same antenna can be difficult, but the example embodiments detailed herein solve this problem in an elegant way which further enables the addition of other secondary radio systems to the antenna, such as for example any combination of one or more of Bluetooth, WLAN and GPS radios.
Example embodiments of the invention may be summarized as a single antenna which in its physical form has a first operational mode that is a balanced mode (for example, a loop antenna) and which also has a second operational mode in which a portion of the antenna operates as a linear radiating element (monopole or similar non-loop structure) in a second operational mode. The first operational mode may be considered to be a balanced mode, whilst the second operational mode may be considered to be an unbalanced mode. It is noted that in the antenna arts, linear does not imply geometrically straight but defines the antenna type: a monopole, a shorted monopole, a dipole, etc., any of which may be along a straight line or which may meander along the length of the radiating element of the overall antenna.
From this basic design are detailed suitable filters and switches which are used in the example embodiments shown at
In certain of the example embodiments at
The combination of antenna having two connection ports with filters and switches can be seen schematically at
Now consider
In the first mode, signals in the NFC band (RFID band, about 13.56 MHz) resonate about the entire antenna Ant1 and signals to and/or from the RFID radio pass through the first and second feed ports P1/P2. The coupling element T1 is configured so as to block signals in the NFC band from passing to the third feed port P3.
In the second mode, signals in the far field band(s) resonate only along a portion of the antenna Ant1 and signals to and/or from the far field radio(s) pass through the coupling element T1 and the third feed port P3. There is a filter which can also be termed an inductance, shown as a FM matching circuit or FM tuning circuit and designated sub-circuit SC1 at
In an example embodiment the physical location along the antenna Ant1 of certain components relative to one another are tailored so that the length of that portion of the antenna Ant1 between such components is resonant in the operational frequency band of a far field radio which interfaces to that portion of the antenna Ant1 . So for example, L2 and SC1 are positioned such that the length of the antenna Ant1 between them is resonant with the FM-RX band, and the FM-RX radio interfaces to that length of the antenna Ant1 at T1.
As shown at
The FM tuning/matching circuit SC1 shown by example at
For the
One technical effect of an example implementation of the coupling element T1 is that it enables the circuit/antenna shown at
In this embodiment the FM reception (FM-RX) signals and the FM transmit signals (FM-TX) are an exception to this simultaneous operation since typically these two radios do not need to operate simultaneously. However, any other combination of radios (Bluetooth, WLAN, GPS, and either TX or RX for FM) can operate simultaneously with the NFC (or RFID) radio.
The reason FM-RX and FM-TX signals need not be operational simultaneously in a mobile handset is explained by an example. It has become popular that personal digital music storage devices are used to provide content to a separate audio delivery system using broadcast FM signals. These broadcasts are exempt from airwave licensing requirements because they transmit with a very low power which severely limits range, for example to one or a few meters. For example, a user may tune the FM radio receiver in a car to a generally un-occupied frequency and broadcast music to that car radio from a low power FM transmitter coupled to one's personal digital music storage device. A user's mobile handset may combine the low power FM transmitter with the personal music storage for such a use. On the reception side, the user's handset may also be configured with a traditional broadcast FM receiver, which can be used to receive traditional FM broadcasts from a licensed radio station or from another low-power FM transmitter of a different handset. For the above case of FM transmissions then, there is no need for simultaneous FM reception by the same handset.
The NFC signals are received or transmitted through the NFC ports which are the first and second feed ports P1 and P2, and the NFC radio (not shown) is connected to those ports P1 and P2. The NFC signals are therefore resonant along the whole of the antenna Ant1 whose ends are defined by the two NFC ports P1 and P2. The coupling circuit T1 blocks the NFC signals from passing toward the third feed port P3. As shown at
The FM-TX (transmit) and FM-RX (receive) signals interface to/from the antenna Ant1 via the third feed port P3 and the coupling element T1. The parameters/values of the inductances L7 and L4 and of the capacitances C4 and C6 are designed such that the FM signal resonates along only a portion of the whole antenna Ant1 , and so therefore the antenna for the FM signals is not operating as a loop antenna but rather a linear, single-ended or unbalanced antenna. As above, these parameters can be fixed and the resonant length is set by physical positioning along the antenna Ant1, or they may be variable and the electrical length is controlled by a processor/controller that varies the parameter (inductance, capacitance) to set the resonant length for the second mode based on which radio that interfaces at T1 is in operation. For the example implementation of
The remaining radios are Bluetooth, WLAN and GPS. Like the FM signals, these also interface to the antenna Ant1 to and from the coupling element T1 via the third feed port P3. The parameters/values of the inductances L4, L7 and L3, and of the capacitance C7, are designed such that the Bluetooth, WLAN and GPS signals resonate along a portion of the whole antenna Ant1 that is an unshorted monopole, also a type of linear antenna. For the example implementation of
Following the embodiment of
In one variation of
There is a low pass filter F1 disposed along the antenna between the first feed port P1 and the first sub-circuit SC1 which in
There is another low pass filter F2 disposed along the antenna between the second feed port P2 and the third feed port, shown at
There is a high pass filter F3 at the feed port P3-1 at which the Bluetooth/WLAN/GPS radios R2 and R3 interface with the antenna, which blocks both RFID signals and FM signals but which allows the Bluetooth/WLAN/GPS signals to pass. This is illustrated as the capacitance C8 at
There is yet another low pass filter F4 at the feed port P3-2 at which the FM radios R4 and R5 interface with the antenna, which blocks both RFID signals and also all of the Bluetooth/VVLAN/GPS signals but which allows the FM TX and RX signals to pass. This is illustrated as the inductance L8 at
We note two qualifications to the test data at
From the above it will be appreciated that according to an example embodiment of the invention there is an apparatus that comprises an antenna Ant1; a first feed port P1 defining a first end of the antenna and a second feed port P2 defining a second end of the antenna; a third feed port P3 coupled to an intermediate point T1 along the antenna (between the first and second ends); an impedance L3 disposed along the antenna and configured such that in a first mode signals (RFID) to or from the first and second ports resonate along the whole of the antenna and in a second mode signals (any one or more of Bluetooth/WLAN/GPS/FM) to or from the third port resonate along a portion of the antenna in which the portion terminates at the impedance.
In one example embodiment of the above apparatus, the propagated signals (those transmitted from or received at the antenna) in the first mode may consist of near field signals having an average range of less than one meter and the propagated signals in the second mode may consist of far and/or near field signals having an average range of at least five meters.
In another example embodiment of the above apparatus, the propagated signals in the first mode may comprise radio-frequency identification RFID signals and the propagated signals in the second mode may comprise at least one of Frequency Modulation (FM) radio signals, global positioning system (GPS) signals, Bluetooth signals, and wireless local area network (WLAN) signals.
In another example embodiment of the above apparatus, the propagated signals in the first mode may define a first frequency band and the propagated signals in the second mode may define a second frequency band different to the first frequency band.
In another example embodiment of the above apparatus, the first mode and the second mode may be active simultaneously.
In another example embodiment of the above apparatus, the first mode is such that the antenna may operate as a balanced antenna and the second mode is such that the antenna may operate as an unbalanced antenna.
In another example embodiment of the above apparatus, the apparatus may further comprise a RFID radio that is operatively coupled to the antenna via the first and second port and no other radios are operatively coupled to the antenna via the first and/or second ports, and a plurality of non-RFID radios that are operatively coupled to the antenna via the third radio port. As used herein, a radio that is operatively coupled to the antenna is arranged to receive input signals from the antenna which the antenna wirelessly received from some other source apart from the radio, and/or to arrange to provide output signals to the antenna for wireless transmission from the antenna.
In another example embodiment of the above apparatus, the impedance may comprise one of a band pass filter or a low pass filter configured to pass signals in the first mode and to block signals in the second mode.
In another example embodiment of the above apparatus, the signals in the first mode may comprise signals in a first frequency band (RFID band), and signals in the second mode may comprise signals in a second frequency band (any one or more of Bluetooth/WLAN and GPS) and signals in a third frequency band (any one or more of FM RX and TX). The first, second and third frequency bands are all different from one another. In this example embodiment the impedance may comprise a first impedance L7 and a second impedance L3 arranged serially along the antenna, in which the first impedance is configured to pass signals in the first and second frequency bands and to block signals in the third frequency band from reaching the second impedance; and the second impedance is configured to pass signals in the first frequency band and to block signals in the third frequency band.
In another example embodiment of the above apparatus, the first impedance may comprise a LC tank circuit.
In another example embodiment of the above apparatus, the second impedance may comprise an inductor.
In another example embodiment, the above apparatus is disposed within a wireless handset device which may further comprise: a RFID radio operatively coupled to the antenna via the first and the second feed ports; at least one of a FM radio, a Bluetooth radio, a wireless local area network radio and a global positioning system radio operatively coupled to antenna via the third feed port; and a cellular radio operatively coupled to a cellular antenna that is separate from the antenna.
According to another example embodiment of the invention there is an apparatus that may comprise antenna means (Ant1); first and second feeding means (P1 and P2) by which the antenna means operates as a balanced antenna (for example, as a loop antenna); third feeding means by which the antenna operates as an unbalanced antenna (for example, as a linear antenna); and filtering means (L3, SC1) for enabling the antenna means to operate as a balanced antenna for signals within a first frequency band (for example, RFID signals) and to operate as an unbalanced antenna for signals within at least a second frequency band (for example, any one or more of Bluetooth/WLAN/GPS/FM signals).
A multiprotocol antenna according to the example embodiments may be disposed in a mobile station such as the one shown at
There are several computer readable memories 14, 43, 45, 47, 48 illustrated there, which may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The digital processor 12 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multicore processor architecture, as non-limiting examples.
Further detail of an example UE is shown in both plan view (left) and sectional view (right) at
Within the sectional view of
The secondary radios (Bluetooth/WLAN shown together as R3, RFID shown as R1, GPS shown as R2, and FM shown as R4/R5) may use some or all of the processing functionality of the RF chip 40, and/or the baseband chip 42. The antenna Ant1 is shown as wrapping partially about a periphery of the housing as was illustrated at
Signals to and from the camera 28 pass through an image/video processor 44 which encodes and decodes the various image frames. A separate audio processor 46 may also be present controlling signals to and from the speakers 34 and the microphone 24. The graphical display interface 20 is refreshed from a frame memory 48 as controlled by a user interface chip 50 which may process signals to and from the display interface 20 and/or additionally process user inputs from the keypad 22 and elsewhere.
Throughout the apparatus are various memories such as random access memory RAM 43, read only memory ROM 45, and in some embodiments removable memory such as the illustrated memory card 47 on which various programs of computer readable instructions are stored. Such stored software programs may for example set the capacitance of the capacitor C7 for the case that a variable capacitor C7 is employed in an example embodiment, in correspondence with transmit and/or receive schedules of the secondary radios. All of these components within the UE 10 are normally powered by a portable power supply such as a battery 49.
The aforesaid processors 38, 40, 42, 44, 46, 50, if embodied as separate entities in a UE 10, may operate in a slave relationship to the main processor 12, which may then be in a master relationship to them. Any or all of these various processors of
Note that the various chips (e.g., 38, 40, 42, etc.) that were described above may be combined into a fewer number than described and, in a most compact case, may all be embodied physically within a single chip.
In an example embodiment of the above method, no radio apart from the first radio is operatively coupled to the antenna via both the first and the second feed ports, and there are a plurality of radios that are operatively coupled to the antenna via the third feed port.
In another example embodiment of the above method, the method further may comprise at block 808 operatively coupling a third radio (any others of the Bluetooth/WLAN/GPS/FM radios) configured to operate in a third frequency band to the antenna via the third feed port. In this instance the above-mentioned impedance comprises a first impedance (L3) and the antenna further comprises a second impedance (L7 within the LC tank circuit SC1) arranged along the antenna serially with the first impedance between the first impedance and the third feed port. The first impedance (L3) is configured to pass signals in the first frequency band (RFID signals) and to block signals in the second frequency band (Bluetooth/WLAN/GPS signals), and the second impedance is configured to pass signals in the first frequency band (RFID signals) and to block signals in the third frequency band (FM signals) from reaching the second impedance.
In another example embodiment of the above method, the method may be directed to making a mobile handset. In this example embodiment there may be the further step at block 810 of operatively coupling a cellular radio (GSM/UTRAN/EUTRAN/VVCDMA/OFDMA for example) to a cellular antenna separate from the antenna and disposing the first radio, the second radio, the cellular radio, the antenna with the inductance, and the cellular antenna within a mobile handset housing. In this context, the term cellular means wireless mobile telephony which uses a hierarchical network.
Consider now
Like the embodiments of
Consistent with
Also at
In the first operational mode, each of those switches S2, S3 couples the antenna Ant2 to the illustrated B port (for balanced mode). Following the diagram of
In the second operational mode, each of those switches S2, S3 couples the antenna Ant2 to the illustrated U port (for unbalanced mode). Following the diagram of
Also in the second operational mode for
The precise location of the inductances L12, L13 along the antenna radiating element Ant2 sets the proper resonant length so as to match with the second frequency band in which the higher band secondary radios operate. Since those inductances L12, L13 are transparent to the FM signals in the third band, their location is irrelevant to those FM signals (to the extent they actually are transparent).
The
Additional circuitry shown at
The third sub-circuit SC3 is shown as comprising two parallel capacitors C10, C11 each coupling opposed ends of an inductance L14 to ground G5. This is a matched circuit for FM band signals that pass to the FM receiver at port P5, and the example of
The fourth sub-circuit SC4 is shown as comprising simply a capacitor but this also is a non-limiting example. The fourth sub-circuit SC4 is a high pass arrangement or component which passes the higher frequency second band (Bluetooth/WLAN/GPS) but blocks the lower frequency third band (FM). Another specific implementation is shown at
Specific embodiments of the fifth sub-circuit SC5 of
While the description of the second switch S2 above assumed it was a single pole dual throw SP2T switch, note that
Noise circles at 100 MHz for the LNA shown at
Embodiments of the invention as described by non-limiting example with reference to
From the above it will be appreciated that according to an example embodiment of the invention consistent with
In this embodiment there are at least two impedances L12, L13 disposed along the antenna and configured such that the antenna, as seen by signals in a second frequency band at the third feed port P6 that are impeded by the at least two impedances L12, L13, is an unbalanced mode for the first throw B of the switches S2, S3 and for the second throw U of the switches S2, S3.
In various particular embodiments the first throw B of the switches S2, S3 interfaces the antenna to the first feed port P4 so as to close a loop antenna at the first feed port P4; and for the second throw U of the switches S2, S3, a first one S3 of the switches interfaces the antenna to the second feed port P5 and a second one S2 of the switches interfaces the antenna to a common potential G6. In the particular
In another particular embodiment the second switch S2 further exhibits a third throw HJ that interfaces a headset coupling jack to the antenna. The apparatus of
Now that the radios are interfaced to the feed ports, further at block 1108 is seen that the first switch and the second switch are moved, simultaneously, to the first throw B in correspondence with a transmission from the transmitter. The other variations and details shown at
The various blocks shown in
In general, the various example embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the example embodiments of this invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as nonlimiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.
It should thus be appreciated that at least some aspects of the example embodiments of the inventions may be practiced in various components such as integrated circuit chips and modules, and that the example embodiments of this invention may be realized in an apparatus that is embodied as an integrated circuit. The integrated circuit, or circuits, may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or data processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the example embodiments of this invention.
Various modifications and adaptations to the foregoing example embodiments of this invention may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and example embodiments of this invention.
It should be noted that the terms “connected,” “coupled,” or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are “connected” or “coupled” together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be “connected” or “coupled” together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.
Furthermore, some of the features of the various non-limiting and example embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and example embodiments of this invention, and not in limitation thereof.
Claims
1. An apparatus comprising:
- an antenna;
- a first feed port defining a first end of the antenna and a second feed port defining a second end of the antenna;
- a third feed port that interfaces to the antenna at an intermediate point between the first and second ends;
- at least two switches, each switch comprising at least a first throw and a second throw, disposed in series along the antenna and configured such that the first throw of the switches renders a balanced mode for the antenna as seen by the first feed port and the second throw of the switches renders an unbalanced mode for the antenna as seen by the second feed port; and
- at least two impedances disposed along the antenna and configured such that the antenna, as seen by signals in a second frequency band at the third feed port that are impeded by the at least two impedances, is an unbalanced mode for the first throw of the switches and for the second throw of the switches.
2. The apparatus according to claim 1, wherein the at least two impedances are disposed in series along the antenna between the at least two switches.
3. The apparatus according to claim 2, wherein the intermediate point lies between the at least two impedances.
4. The apparatus according to claim 2, wherein the first port is coupled to a FM radio transmitter and the second port is coupled to a FM radio receiver and the second frequency band is higher in frequency that a FM radio band.
5. The apparatus according to claim 1, in which the first throw of the switches interfaces the antenna to the first feed port so as to close a loop antenna at the first feed port.
6. The apparatus according to claim 5, in which for the second throw of the switches, a first one of the switches interfaces the antenna to the second feed port and a second one of the switches interfaces the antenna to a common potential.
7. The apparatus according to claim 6, the apparatus further comprising a sub-circuit disposed between the second one of the switches and the common potential.
8. The apparatus according to claim 6, in which the sub-circuit defines which type of unbalanced mode antenna is seen by the second feed port.
9. The apparatus according to claim 6, in which the second switch further exhibits a third throw that interfaces a headset coupling jack to the antenna.
10. The apparatus according to claim 1, further comprising a matching circuit disposed between the intermediate point of the antenna and the third feed port.
11. The apparatus according to claim 10, in which the matching circuit is configured to block signals in a third frequency band that are sent to or received at the first and second feed ports and further configured to pass signals in a second frequency band that is higher than the third frequency band.
12. The apparatus according to claim 1, characterized in that the apparatus lacks any feed port for coupling any cellular radio.
13. The apparatus according to claim 1, disposed within a wireless handset device which further comprises:
- a FM radio transmitter operatively coupled to the antenna via the first feed port;
- a FM radio receiver operatively coupled to the antenna via the second feed port;
- at least one of a Bluetooth radio, a wireless local area network WLAN radio and a global positioning system GPS radio operatively coupled to the antenna via the third feed port; and
- a cellular radio operatively coupled to a cellular antenna that is separate from the antenna.
14. A method comprising:
- operatively coupling a transmitter to an antenna in a balanced mode via a first feed port and a first throw of a first switch and a first throw of a second switch;
- operatively coupling a receiver to the antenna in an unbalanced mode via a second feed port and a second throw of the second switch;
- operatively coupling at least a second radio, configured to operate in a frequency band different from the transmitter and from the receiver, to the antenna via a third feed port that interfaces to the antenna at an intermediate point between the first switch and the second switch; and
- moving the first and second switches to the first throw in correspondence with a transmission from the transmitter.
15. The method according to claim 14, wherein the transmitter and receiver are configured to operate in a third frequency band that is lower than a second frequency band in which the second radio is configured to operate.
16. The method according to claim 14, in which no radio apart from the transmitter is operatively coupled to the antenna via both the first and the second feed ports, and there are a plurality of radios that are operatively coupled to the antenna via the third feed port.
17. The method according to claim 14, in which the transmitter is a FM radio transmitter, the receiver is a FM radio receiver, and the second radio is selected from the group consisting of global positioning system GPS radio, Bluetooth radio, and wireless local area network WLAN radio
18. The method according to claim 14, in which the first throw of the first switch and the first throw of the second switch interfaces the antenna to the first feed port so as to close a loop antenna at the first feed port.
19. The method according to claim 14, in which a third throw of the second switch interfaces the antenna to a headset coupling jack.
20. The method according to claim 14, in which the second throw of the first switch interfaces the antenna to the second feed port and the second throw of the second switch interfaces the antenna to a common potential.
Type: Application
Filed: Apr 30, 2010
Publication Date: Nov 4, 2010
Applicant:
Inventors: Jouni Karkinen (Oulu), Hannu Laurila (Oulu), Jouni Hanninen (Kiviniemi)
Application Number: 12/771,174
International Classification: H04M 1/00 (20060101); H01Q 9/00 (20060101); H01Q 3/24 (20060101); H04B 1/38 (20060101);